Missing 'product not found' error

[annasoracco]

Describe the bug
A clear and concise description of what the bug is.

To Reproduce
Steps to reproduce the behavior:

1. Go to any existing product detail page
2. Add additional digits to product sku number in URL
3. site continues to cycle (no error message)

Expected behavior
"Product not found" or similar generic message.

Screenshots
If applicable, add screenshots to help explain your problem.

[mithunshanbhag]

For an invalid productID, the API is rightly returning a 404.

However, the UI doesn't seem to have a handler for this error.

This is the line of code in question.

Can you add a handler to redirect to the 404 page?

[mithunshanbhag]

Resolved with #205